doing this in my mcp studies, pro includes the following that home doesnt;
dynamic disks,
remote desktop
ntfs and print permissions
encrypting file system,
domain membership
dual processors
iis
straight out of a microsft training kit.
EDIT: you can use it, it may require you to reinstall windows (imo, best to do it anyways when changing this much hardware). It will prob bluescreen when you boot with new hardware. this is caused by HAL (hardware abstraction layer)